The product - which was being sold at Kmart Australia, in its kids' book section - has images of a penis inside a vagina and a woman lying on top of a man mid-coitus.

Photo credit: Facebook / Auburn 2144

A Facebook post about the book, which is written by cartoonist Fiona Katauskas, expresses total shock about why it appeared in a section frequented by children.

Many commenters backed the poster up.

"There is a classification for watching TV in what age groups can see. Why the F*** is this book shelved for children?" one wrote.

"Lolz at all the morally bankrupt white people supporting this filth, I'm hoping they don't have children yet and when they do they'll realise that their kids don't have any use for this information," another said.

However many were supportive of the book, saying it was a good educational tool - and better for children to learn about sex that way, rather than through a fellow child at school.